thalmiclabs/myo.js

Myo javascript bindings

myo.js

North (formerly Thalmic Labs), the creator of the Myo armband, was acquired by Google in June 2020. Myo sales ended in October 2018 and Myo software, hardware and SDKs are no longer available or supported. Learn more.

Myo javascript bindings.

Myo.js allows you to interact with Thalmic Labs's Myo Gesture Control Armband using websockets. Listen for IMU, EMG, and gesture events, as well as controlling vibration and locking.

installation

On the browser, just include the myo.js file in your project. Myo will be global.

On node.js

npm install myo ws

getting started

You'll need a Myo and Myo Connect

Client-side

Myo.connect('com.stolksdorf.myAwesomeApp');

Myo.on('fist', function(){
	console.log('Hello Myo!');
	this.vibrate();
});

Node

var Myo = require('myo');

Myo.connect('com.stolksdorf.myAwesomeApp', require('ws'));

Myo.on('fist', function(){
	console.log('Hello Myo!');
	this.vibrate();
});

myo lifecycle

A myo can be paired, connected, and/or synced.

A myo is paired if it's ever been connected to your computer. You can see a list of paired myos in Myo Connect's armband manager. When Myo.connect() is called, Myo.js will create a myo instance for every paired Myo on your computer and store them in Myo.myos array.

A myo is connected if it's turned on and connected to your computer over bluetooth. It can send over IMU events at this point, vibrate, and EMG (if myo.streamEMG(true) is called) but not poses since it's not synced with the user.

A myo is synced when the user puts it on and does the sync gesture. At this point it will start sending over pose and lock/unlock events.

branding and assets

You can use assets provided in our branding and UX guidelines.

documentation

You can read the full documention in docs.md

changelog

Releases are documented in changelog.md

thanks

Thanks to stolksdorf for creating Myo.js

myo.js's Issues

Myo.js had an error with the socket

Hello

I struggled quite a bit with connecting to Myo from node.js. No matter what, I got the error message Myo.js had an error with the socket. Myo Connect might not be running. If it is, double check the API version.Myo.js had an error with the socket. Myo Connect might not be running. If it is, double check the API version..

After a while, I tried removing the "app id" in my.connect("my-app-id"), and suddenly it worked. Turns out it crashes if you have less than 3 dot-separated words in your app id (i.e. "my.app.id"). This might be common sense, I don't know, but I can't see any mention of it in the documentation. Also, the error message is not very helpful. I debugged it a bit (add console.log(arguments) between line 20 and 21 in myo.js), and it seems the websocket started by Myo Connect returns 400 if you have less than 3 dot-separated words in your app id.

Only trigger pose events from 'rest' state?

Is it possible to configure the myo lib to only trigger a pose event from the rest state? I'm having issues were during a sustained fingers_spread suddenly a wave_out is detected after which the fingers_spread off event won't be sent when I go back to the rest pose. I'll then have trigger fingers_spread again and release (without any other poses interfering) in order to catch the fingers_spread off event. How to prevent this from happening?

Add examples to Experimental

Each experimental feature should have it's own example you can run.

Some myos won't get detected by Myo.js

This is caused by the user not creating enough myo instances to handle all possible myo-index ids from Myo Connect. The library should handle this under the hood, and hide the myo-index from the user. User should use mac address as the identifier for the myo instances

How to unlock() permanently?

According to the docs, unlock() should do an infinite unlock. But the myo band locks after 3 seconds. How can I actually unlock it forever?

Is it possible to connect to the MyoConnect WebSocket server from a non localhost address.

I've been trying to connect to the myo web socket server running on my windows desktop from a webpage running on my Android device, by updating the ip address in myo.js, but I can't seem to connect.

Does Myo Control actively reject such requests ?

npm module myo.js crash due to [email protected], suggest to upgrade it to [email protected]

In the npm module, myo.js uses [email protected] by default, however it crashes after running several seconds.

Error message:

SyntaxError: Unexpected end of JSON input
    at Object.parse (native)
    at WebSocket.handleMessage (/Users/xuji/Desktop/home_automation/myo_control_client/node_modules/myo/myo.js:60:20)
    at WebSocket.onMessage (/Users/xuji/Desktop/home_automation/myo_control_client/node_modules/ws/lib/WebSocket.js:355:18)
    at emitTwo (events.js:106:13)
    at WebSocket.emit (events.js:191:7)
    at Receiver.self._receiver.ontext (/Users/xuji/Desktop/home_automation/myo_control_client/node_modules/ws/lib/WebSocket.js:682:10)
    at Receiver.finish (/Users/xuji/Desktop/home_automation/myo_control_client/node_modules/ws/lib/Receiver.js:391:14)
    at Receiver.expectHandler (/Users/xuji/Desktop/home_automation/myo_control_client/node_modules/ws/lib/Receiver.js:378:31)
    at Receiver.add (/Users/xuji/Desktop/home_automation/myo_control_client/node_modules/ws/lib/Receiver.js:87:24)
    at Socket.firstHandler (/Users/xuji/Desktop/home_automation/myo_control_client/node_modules/ws/lib/WebSocket.js:663:22)

After googling, I found out [email protected] will crash with [email protected] and above. Thus, I upgraded ws in myo module, and it never crashed ever since.

Please use [email protected] as default in npm module if possible. Thanks!

Throw error if no myo present

It'd be nice if you could wrap the Myo.create() in a try/catch to tell if there is a myo in the system. Consider throwing an error if the connection to the localhost server fails such that the error could be caught to tell if there's no myo present.

The 'catch-all' event listeners modifys the arguments for subsequent listeners

From @stolksdorf on February 11, 2015 15:21

myo.on('*', function(){})
myo.on('pose', function(){}); //this will have the wrong arguemnts

Possible fix: use a standard events library.

Copied from original issue: stolksdorf/myo.js#18

Add Myo Point experiment

We should translate the Myo Point code (for mouse tracking) into JS for a good demo

Add better gesture events aka remove 'edge'

The gesture events are slightly confusing with the edge parameter. Replace them with a fist and fist_off like events.

License

Hello,

package.json states that the code is licensed under ISC.

However, the LICENSE.txt looks like a BSD 3-clause license.

The README states "The Myo.js project is licensed using the modified BSD license" - which would fit both ISC and BSD3.

Could you please clarify which license is used and please fix either the package.json or the LICENSE.txt?

Getting started guide

Repurpose Paul's great blog post into a getting started guide

graph output in the imu example is wrong

You can use this simple patch.

http://www.mat-chemnitz.de/explodus.patch

Please add option to override the onError handler

We are building an application that supports many different gesture input devices. As the user does not necessarily have a Myo band, connecting to Myo Connect may fail.

In this case, the library throws an error which is not easy to catch, since it is thrown async. In my case, this caused the EventEmitter of ws to fail, and it was quite hard to track down the source of this problem.

For the time being, I'm working around this by manually overwriting Myo.onError, but it would be better if there was a way to explicitly call Myo.on('error', fn).

PS: The current behaviour of throwing in case of an error is not a good idea. It's not possible to catch this in a regular try catch due to its async behaviour. It would be better if just an error messages would be printed on the console.

Failed on HTTPS sites.

From @PhillippOhlandt on February 26, 2015 21:39

Hey I want to build myo control on my websites wich use https.

The websocket cannot be initiated.

Uncaught SecurityError: Failed to construct 'WebSocket': An insecure WebSocket connection may not be initiated from a page loaded over HTTPS.

Copied from original issue: stolksdorf/myo.js#23

two myo devices

Hello is there some way to configure two myo devices using myo js?

Code mistake in Experimental

In the experimental readme, the example for Myo Tap has myMyo.unlock() when it should have myMyo.lock(). It is currently

//Myo tap to lock and unlock!
myMyo.on('myo_tap', function(){
    if(myMyo.isLocked){
        myMyo.unlock();
    }else{
        myMyo.unlock();
    }
});

when it should be

//Myo tap to lock and unlock!
myMyo.on('myo_tap', function(){
    if(myMyo.isLocked){
        myMyo.unlock();
    }else{
        myMyo.lock();
    }
});

Also toggling the lock state is common enough that you might want to add a function to do it (to prevent mistakes like these.)

Connecting Myo with Myo Connect ?

Hello ; Can we use "Myo" without using Myo Connect ? can it be independent ?